The present invention relates to hinge mechanisms for vehicle seats, and more particularly, to an improved vehicle seat hinge mechanism having reclining, forward dumping with memory return, and fold-flat functionality.
Passenger vehicles commonly have vehicle seat assemblies provided with both reclining and forward dumping functionality which permits the seat back to be selectively reclined about a lower pivot axis through a range of substantially upright, occupiable positions for selection by the user of a preferred seating position, and to also be rapidly tilted forwardly about said lower pivot axis to a so-called xe2x80x9cdumped positionxe2x80x9d at which dumped position the seat back is forwardly tilted to an unoccupiable position that projects in vertically angled relation over the seat cushion, so as to facilitate ingress and egress to and from the interior space in the vehicle to the rear of the seat assembly.
Such vehicle seat assemblies typically comprise a pair of vehicle seat hinge mechanisms disposed on opposite lateral sides of the vehicle seat assembly, with each such hinge mechanism having a seat cushion mounting plate securely attached to the seat cushion and a sector plate operatively securely attached to the seat back.
The two hinge mechanisms of each pair are typically connected to one another by a system of slave rods or cables, as is well-known in the art, for simultaneous actuation, thereby to reduce the total number of user handles required to control all functions of the pair of vehicle seat hinges associated with each seat assembly.
Rotary recliners are commonly utilized in hinge mechanisms to provide for controlled reclining of the seat back about the lower pivot axis in the general manner discussed above. Advantages of known rotary recliners include that they are relatively inexpensive to manufacture, have their working components substantially enclosed (which lends to their reliability and safety), are relatively lightweight, and fit into a relatively small design envelope. One suitable rotary recliner is disclosed in U.S. Pat. No. 6,336,679 (Smuk et al.), issued Jan. 8, 2002, which is incorporated herein by reference.
Sometimes, it is desirable that a seat assembly also be provided with xe2x80x9cmemory returnxe2x80x9d functionality, such that once a preferred seating position has been selected by a user, the seat back locks automatically when it returns to the preferred position after a dumping operation.
Vehicle seat assemblies utilizing rotary recliners and also providing memory return functionality are not generally known in the prior art. Rather, most prior hinge mechanisms having rotary recliners and providing memory return functionality typically rely upon relatively bulky stamped metal components external to the rotary recliner that can be expensive and difficult to assemble, which add excessive weight to the vehicle seat assembly, or comprise complicated systems of master and slave adjustment rods, such as the system disclosed in U.S. Pat. No. 6,315,361 (Stone et al.), issued Nov. 13, 2001.
Combined passenger and utility type vehicles, such as mini-vans and sport utility vehicles, commonly have a second and sometimes a third row of seats that additionally have xe2x80x9cfold-flatxe2x80x9d functionality, which also permits the seat back to be tilted forwardly about a higher pivot axis displaced above said lower pivot axis to a fold-flat position, whereat the seat back substantially overlies the seat cushion in generally horizontal relation. In such position, the back surface of the seat back constitutes a load bearing surface. Thus, placing a seat back in its fold-flat position facilitates carriage of large or lengthy objects inside the vehicle and provides a convenient, substantially horizontal, load bearing surface for articles that might be found in said vehicle, such as briefcases, laptop computers, and food and drink. Generally speaking, with most vehicle seat assemblies, the back surface of the seat back is not sufficiently horizontal during a dumping operation to provide a safe load bearing surface, as it retains a significant degree of vertical inclination about the lower pivot axis relative to the seat cushion. For this reason, pivoting of the seat back about the aforementioned higher pivot axis, which is upwardly displaced from the first pivot axis, is generally required to provide for a sufficiently horizontal orientation of the load bearing surface formed by the back surface of the back rest.
Accordingly, it is an object of the present invention to provide an improved vehicle seat hinge mechanism that provides the functionality of a rotary recliner, forward dumping, and a return memory feature, all in a compact, simple device that is reliable, cost-effective, lightweight, smaller, easy to manufacture by mass production methods, and simple to assemble as compared to prior art devices having similar functionality.
In accordance with the present invention there is disclosed an improved vehicle seat hinge mechanism for use in a vehicle seat assembly. The improved vehicle seat hinge mechanism has a seat cushion mounting plate, a rotary recliner, a sector plate and a seat back mounting plate. The seat cushion mounting plate is securely attachable to a vehicle seat cushion. The rotary recliner has a first portion and a second portion. The first portion defines a lower pivot axis and is rigidly attached to said seat cushion mounting plate. The second portion is mounted to the first portion for selective pivotal movement relative thereto about said lower pivot axis under the control of a recliner actuation handle. The sector plate is operatively mounted on the second portion of the rotary recliner for selective pivotal movement therewith about the lower pivot axis under the control of said recliner actuation handle, as aforesaid, thereby defining a first modality of pivotal movement of said sector plate about said lower pivot axis. The seat back mounting plate is operatively mounted on said sector plate and securely attachable to a vehicle seat back.
The improved vehicle seat hinge mechanism disclosed herein provides, when installed in said vehicle seat assembly and through the agency of said sector plate moving in said first modality, for said seat back to be pivotally movable with respect to said seat cushion about said lower pivot axis within a range of angular positions including a preferred seating position, a fully-inclined position and a fully-reclined position.
According to one aspect of the invention, the improvement comprises having the sector plate being mounted on said second portion of the rotary recliner as aforesaid by means of an idler plate.
The idler plate is so mounted in fixed relation to said second portion for selective simultaneous pivotal movement of the sector plate, the idler plate and the second portion about said lower pivot axis under control of the recliner actuation handle in said first modality. The idler plate has a bearing surface to which the sector plate is journalled to provide for pivotal movement of said sector plate relative to said idler plate about the lower pivot axis between a first position and a second position, thereby to define a second modality of pivotal movement of the sector plate about said lower pivot axis and to provide, when said improved vehicle seat hinge mechanism is installed in said vehicle seat assembly and through the agency of said sector plate moving in said second modality, for said seat back to be pivotally movable with respect to said seat cushion about said lower pivot axis between a primary position, whereat the sector plate is at its first position, and a secondary position, tilted forwardly relative to the primary position, whereat the sector plate is at its second position.
The improvement further comprises having a quick-release actuation member, a first lock means for selectively releasably locking the sector plate at its first position relative to the idler plate to prevent movement of the sector plate in said second modality, such release being under control of said quick-release actuation member, and first bias means for causing said locking of the first lock means.
Thus, when the improved vehicle seat hinge mechanism is installed in the vehicle seat assembly, it provides reclining functionality by permitting, under control of the recliner actuation handle, pivotal movement of the seat back to a preferred seating position within the range of available angular positions, by way of the sector plate moving in said first modality. Release of the recliner actuation handle by the user when the seat back is at the preferred position causes the rotary recliner to again lock up to hold the seat back in said preferred seating position.
The improved vehicle seat hinge mechanism disclosed herein further provides dumping functionality by permitting, under control of the quick-release actuation member, the seat back to be tilted forwardly from said selected position towards a forwardly dumped position, whereat the seat back overhangs the seat cushion, by agency of said sector plate moving in said second modality. It further provides for seat back memory by means of activation of said first lock means upon return of the seat back in said second modality to said selected position after a dumping operation.
According to another aspect of the invention, preferably, the sector plate defines an upper pivot axis and the seat back mounting plate defines a seat back axis and is mounted on said sector plate for pivotal movement, about said upper pivot axis and relative to the sector plate, between an extending position, whereat the seat back axis is arranged substantially radially relative to the lower pivot axis, and a nesting position, substantially transverse to the extending position. This provides, when said hinge mechanism is installed in said vehicle seat assembly, for fold-flat functionality, by providing for said seat back to be pivotally movable with respect to said seat cushion, by agency of said seat back mounting plate pivotally moving between its extending position and its nesting position, between a substantially upright position within the range and a fold-flat position, whereat the seat back substantially horizontally overlies the seat cushion.
According to a further aspect of the invention, the hinge mechanism preferably further comprises a second lock means for selectively releasably locking the seat back mounting plate at its extending position.
According to yet a further aspect of the invention, the hinge mechanism preferably further comprises an actuation means for releasing the second lock means, under control of the recliner actuation member, upon pivotal movement of the seat back to the upright position from a triggering position which is tilted rearwardly relative to the upright position.
According to yet another aspect of the invention, the hinge mechanism preferably further comprises a recliner actuation handle operatively mounted to the first portion of the rotary recliner for pivotal movement between a rest position and an in-use position and operatively connected to the rotary recliner so as to permit said pivotal movement of the second portion of the rotary recliner upon movement of the recliner actuation handle away from the rest position.
According to still another aspect of the invention, the quick-release actuation member is preferably a quick-release actuation handle, operatively pivotally mounted to the upper part of the sector plate for movement between a rest position and a dumping position and operatively connected to the first lock means to release same upon movement to the dumping position.
Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, which are briefly described hereinbelow.